A Flavonoid-Rich Bounty: Looks Good, Tastes Good, and Good for You!

Wednesday, July 27, 2011

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Warm weather has arrived, and it’s time for the delicious foods that we associate with the sunny days of spring and summer: sweet blueberries, blackberries, strawberries, and raspberries; succulent plums, apricots, pluots, peaches, and nectarines; deep red Bing or bright yellow Rainier cherries; flavorful red and black grapes, velvety mangoes and kiwi; and juicy watermelons. And there’s so much more: sweet yellow or red onions, pungent garlic, dark leafy greens and lettuces, red tomatoes, green zucchini squash, and bright yellow crookneck squash. (I could go on and on, but I fear you may abandon your reading of this blog entry to head to the farmer’s market!)

What do all of these wonderful foods have in common? Well, for one, they’re all colorful due to the fact that that contain plant pigments known as flavonoids. There are several types of flavonoids, and different foods vary in the types of flavonoids that they contain. For example, red and purple berries and grapes contain anthocyanidins; yellow onions and kale contain flavonols. No matter the type, flavonoids are an exciting area of nutritional research. Because of the high content of flavonoids in fruit- and vegetable-rich diets, scientists are investigating how they contribute to the health benefits associated with such diets. Some of the findings are described below:

Regulation of cell processes. Flavonoids can regulate cell growth, proliferation, and death by controlling the biochemical events that lead to changes in the expression of specific genes. Through this action, flavonoids may inhibit the productions of proteins associated with chronic diseases.

Cardiovascular benefits. Flavonoid-containing foods have been shown to increase the production of nitric oxide by endothelial cells in blood vessel walls. Nitric oxide promotes the vasodilation (relaxation) of arteries; it also decreases the stickiness of platelets, one of the first steps in clot formation. Both of these effects are desirable in the treatment and prevention of coronary artery disease.

Cancer prevention. High dietary intakes of some flavonoids have been found to be inversely related to the risk of certain cancers. It is thought that the flavonoids act by inhibiting the proliferation and promoting the death (apoptosis) of cancer cells.

Neurodegenerative disease prevention. Flavonoids also possess antioxidant, metal-chelating, and anti-inflammatory properties that make them potential protectors against neurodegenerative diseases like Parkinson’s and Alzheimer’s. Flavonoids have also been associated with improved cognitive performance and decreased age-related cognitive decline.

So fill your plate with colorful fruits and vegetables: They look good, taste good, and they’re good for you! And complement your healthy plate with white, green, or black teas to drink and chocolate for dessert; they’re rich in flavonoids, too!

Karen Brothers, ND student, NCNM

For more information about flavonoids, see the Linus Pauling Institute’s web page about flavonoids.

Labels: flavonoids, fruits, health benefits, vegetables

posted by Innate Response at

10:12 AM

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Alzheimer’s Disease: Genetics or Lifestyle?

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Are our genes our destiny? Several publications have recently concluded that, no, our genes are not always the culprit in the progression of disease. According to the publications, nutritional status and diet appear to play a very large role in the development of neurodegenerative diseases, especially Alzheimer’s disease. A four-week dietary intervention study conducted in Seattle, WA was published in the June issue of the Archives of Neurology. The researchers discovered that healthy individuals who consumed a diet that was both low in saturated fat and full of foods that have a low glycemic index had significant decreases in the levels of Beta-amyloid 42 in their cerebrospinal fluid. Beta-amyloid 42 is used clinically as a biomarker for Alzheimer’s disease risk and cerebrospinal fluid (CSF) is the fluid that nourishes the brain and spinal cord. It is especially shocking that the results were scientifically significant after only four weeks of intervention. The study provided every bite of food consumed by the study participants. The unhealthy diet, which was high in saturated fat and simple carbohydrates, specifically contained 45% fat (25% saturated fat), 35-40% carbohydrates and 15-20% protein. The healthy diet, with a low glycemic index and low saturated fat levels, contained 25% fat (less than 7% saturated fat), 55-60% carbohydrates and 15-20% protein. 24 participants stuck to the high fat diet while 25 were put on the low fat diet. The authors noted that the high fat diet moved beta-amyloid 42 levels “in a direction that may characterize a presymptomatic stage of Alzheimer’s disease before plaque deposition.” They also noted that the low fat diet had “striking effects” and significantly lowered the beta-amyloid 42 levels in the CSF of those participants who consumed the low fat diet.

Also, in a review that was just published in March, investigators conclude that “HHcy [(hyperhomocysteinemia or high homocysteine levels)] has been established as a risk factor and a risk marker for neurodegenerative diseases. Hcy [(homocysteine)] is a surrogate marker for B vitamin deficiency, and in addition it also appears to be able to predict the occurrence and progression of dementia.... HHcy is among the most promising environmental risk factors for dementia which can be lowered easily by vitamin B therapy.” As mentioned by the authors, high homocysteine levels can be caused by low levels of important nutrients, particularly B vitamins. Homocysteine is naturally formed from the amino acid methionine when a methyl group is lost from the methionine during normal metabolism. B vitamins are necessary to re-methylate the homocysteine back to the very safe amino acid methionine. If there is a deficiency in B vitamins, due to either dietary inadequacy or malabsorption, homocysteine levels will increase since the vitamin B-dependent methyl donors are unable to convert the toxic homocysteine back into methionine. These high homocysteine levels are a risk factor for neurodegeneration. The authors of this study also clearly state that “genetic factors do not explain or predict the majority of cases” of Alzheimer’s disease which means that environmental factors most likely play the key role in its development. Now that researchers are slowly uncovering the (seemingly) direct correlation between nutritional status and neurodegenerative diseases such as Alzheimer’s disease, there is yet another compelling reason to incorporate a low-fat, low-sugar whole foods diet full of valuable nutrients into your daily lifestyle. Oh and, if your grandfather has Alzheimer’s disease it doesn't mean that you will too!!! Eat your veggies.

References

Arch Neurol. 2011; 68:743-752.

Clin Chem Lab Med 2011;49(3):435-441.